Standing wave ratio control apparatus



Aug. 19, 1958 F. KULICK 2,848,692

STANDING WAVE RATIO CONTROL APPARATUS Filed June 20, 1955 2 Sheets-Sheet 1 Ha g lNVE/VTDR FREDERICK KUL/CK Arrok/vsr Aug. 19, 1958 F. KULICK 2,843,692

STANDING WAVE RATIO CONTROL APPARATUS Filed June 20, 1955 2 Shets-Sheet 2 MICRO- METER FREQUENCY (MEGACVCI. ES)

FIG 5 i 40 COMAJON I 48 60 1 W9 wim H M U22 as 2 w i 5/ 5a r INVENTOR Z 4 FREDERICK KUL/CK .J L j t 22 By ATTORNEY United States Patent STANDING WAVE RATIO CONTROL APPARATUS Frederick Kulick, Coopersburg, Pa., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application June 20, 1955, Serial No. 516,641

3 Claims. (Cl. 333-17) This invention relates to standing wave ratio control apparatus and particularly to apparatus for automatically controlling the standing wave ratio in the output wave guide of a magnetron or other oscillatory device having externally driven tuning means.

Like other mass produced electron discharge devices,

magnetrons are subjected to a number of inspections and the output frequency of the devicesin suchtests, an.

operators services have been requiredheretofore for the duration of the test, for making periodic adjustments in standing wave control apparatus.

The object .of this. invention is. an automatic control for the standing wave ratio in the output wave guide of such devices.

In accordancewiththe general featuresof the invention, the standing wave ratio in the output wave guide of such externally tunable oscillatory devices may be varied by an incrementally adjustable standing wave introducer, the operation; of which. is controlled directly by the driver for tuning. the oscillatory device. The

introducer is periodically adjusted in synchronism. with the tuning of the device in order to approximate a desired standing wave ratio over the operating frequency range.-

These and other features of the invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawing, in which:

Fig. 1 is a front elevation view of the tuning drive mechanism and the mechanism for controlling the opera v tion of the standing wave introdu-cer;

Fig. 2 is a side elevational view of the introducer control mechanism portion of Fig. 1;

Fig. 3 is an elevational view of the cavity portion of the standing wave introducer;

Fig. 4 is 'a curve showing the relationship between the standing wave introducer micrometer setting vs. frequency, and

Fig. 5 is a diagrammatic view of a control circuit for the device.

Referring now to the drawing particularly Figs. 1, 2 and 3, a motor 7 mounted on a fixed support 6 drives a flexible shaft 8 for tuning a magnetron, which may be of the Western Electric Company type 5780, and also rotates a lead screw 9 which controls the actuation of a switch 10 mounted on a movable element 11 which is driven along the screw. A slip clutch 12 is positioned "ice between the lead screw and the motor 7 to prevent injury to the apparatus in case of jamming in the tuning drive mechanism. A quick release coupling 14 which may be disconnected by lifting an actuator arm 15 therefor, is provided for disconnecting the motor 7 from the lead screw to facilitate setting up the system. A hand wheel 16 permits making manual adjustments to the lead screw 9 and flexible shaft 8 through bevel gears 17 and 18.

A fixed shaft 19 for a plurality of cams 20 through 28 is mounted to brackets 29 and 30 which are secured to the fixed support 6. The cams 20 through 28 are slidable along the shaft 19 and are provided with set screws 30 to lock them in position thereon. The cams actuate the switch 10 periodically when the element 11 traverses along the lead screw 9.

A cavity-plunger adjustable standing wave introducer, as seen in Fig. 3, comprises a wave guide contacting member 31 which is supported on the magnetron output wave guide 32. A cavity housing 33 is provided with a plunger 34 (shown in dashed lines) which may be adjustably positioned by the micrometer screw movement 35 for varying the size of the introducer cavity 36 which is adjacent to a slot (not shown) in the wall of the wave guide. A motor 37, which may be suitably mounted close to the introducer, utilizes a flexible shaft 38 for rotating micrometer screw 35 for adjusting the plunger 34 in the cavity. Acircular cam 40 attached to the rotatable handle 41 of the micrometer screw 35 has a plurality of equally spaced detents 42 around its periphery and a switch 45 on support members 46 and 47 attached to the member 31 of the introducer is provided with an actuator 48- which rides on the cam 40.

While performing the life test it is necessary to maintain a substantially constant standing wave ratio i. e. 1.5, in the output wave guide. The curve 49 of Fig. 4 represents a constant standing wave ratio of 1.5 in the output wave guide of a 5 780 type magnetron. This graph shows the micrometer settings required for the introducer for the different frequencies of oscillation for the magnetron over its operating range, in this case 8,500 to 9,600 megacycles. The earns 20 through 28 for the reciprocat ing switch 10 are adjusted so that the switch is energized at specified frequencies to energize the micrometer adjusting motor 37 for moving the plunger. The motor moves the plunger in equal increments or steps as shown in-Fig. 4 to produce a curve 69 which approximates the curve 49 for the constant 1.5 standing wave ratio. The vertical dimensions denoted 21' through 28 of the approximating curve 69 correspond to the micrometer adjustment caused by cams 20 through 28 respectively.

To result in such a curve, the cams are positioned on the In the present instance, detents are spaced for rotating the cam five divisions as read on the micrometer. The operation of the micrometer motor will be described in detail below in conjunction with the description of the control circuit of Fig. 4.

Referring now to the control circuit of Fig. 5, motor 7, which drives the lead screw 9 and the magnetron tuning shaft'S, is a constant speed reversible motor energized from the A. C. Source 51 through the transfer contacts 53 of reversing relay 54. The movable contact member 55 of switch 10, which is connected to one ter-' minal 56 of the A. C. source'Sl, connects this side of the source to one side of the windingsof relays 57 and 58 when the switch 10is closed by contacting the cams 20 through 28. The other sides of relays 57 and 58areconnected directly to the other terminal 59 of the source 51. Relay 57 is a slow operating relay which operates in about two seconds and relay 58 is a regular fast operating relay. When relay 58 operates, under the control of switch 10, its normally open contacts 60 close to energize motor 37, an A. C. reversible shaded-pole type motor which drives the introducer micrometer screw, through the normally closed' contacts 61 of relay 57. Transfer contacts 62 determine the direction of rotation of motor 37 depending on the condition of relay 54. Switch 45 on the introducer is normally open when its actuating arm 48 is positioned in one of the detents 42 of the cam 40 and is connected in parallel with the normally closed contacts 61 of relay 57. A normally closed reversing switch 66 on the cam support bracket29 is connected between the terminal 56 of the source 51 and the one side of the winding-of relay 54. A second nor mally open reversing switch 64 is connected to the other side of relay 54 and terminal 59 of the source 51. Lock-up contacts 52 are provided on relay 54 for holding the relay 54 operated after switch 64 has been closed and before switch '62 has been opened.

In operation, motor 7 which is provided with a gear reducing arrangement .(not shown) normally operates to rotate the lead screw so that the magnetron may be tuned through its entire range from 8,500 to 9,600 megacycles once every 24 hours. When the switch is operated by one of the cams through 28 relay 58 immediately operates to close its contacts 60 to energize motor 37 through the normally closed contacts 61 of relay 57 and the transfer contacts 62 of relay 54. Due to theextremely slow movement of element 11 on worm 9, the energizing pulse supplied by switch 10 to relays 57 and 58 is continuous for a relativelylong time, approximately fifteen minutes, while only about three secends is required for motor 37 to index the cam 40 through one detent, Relay 57 will open its normally closed contacts 61 after two seconds which allows switch 45 to open the circuit supplying power formotor 37 when the actuator arm 48 of switch 45 drops into one of the detents 42. Motor 37 will drive the cam 40 from one detent to the next in about three seconds. Limit switches 62 and 64 areactuated by the element 11 when it is moved to the ends of its path of travel on worm 9 to energize the reversing relay 54 which operates to reverse the direction of rotation of both motors.

'It is to be understood that the above described -arrangements are simply illustrative of the application. of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the inven-' tion and fall within the spirit and scope thereof.

What is claimed is:

1. Apparatus for automatically controlling the standing wave ratio in the output wave guide of an externally tunable oscillatory device having a driver for tuning the device for oscillation over a frequency range, comprising an adjustable standing wave introducer for the wave guide, a motor for adjusting the introducer, control means for energizing the motor to make an incremental adjustment in the introducer, and means controlled by the driver for selectively actuating the control means when the device is tuned for oscillation at predetermined frequencies.

2. Apparatus for automatically controlling the standing wave ratio in the output wave guide of an externally tunable oscillatory device having a driver for tuning the device for oscillation over a frequency range, comprising a standing wave introducer having a cavityand a mov-- able plunger therefor for varying the standing wave ratio in the wave guide, a motor for positioning'the plunger in the cavity, switching means for de-energizing the motor whenever the plunger is moved a prescribed amount and means controlled by the driver for selectively energizing the motor when the device is tuned for oscillation at predetermined frequencies.

Whenever the plunger is moved a prescribed amount, a

switch for controlling the'energizing of the introducer motor, a worm driven by the tuning driver for reciprocating the switch over a fixed path and a plurality of cams adjustably positioned along the path for actuating the switch. p

4. Apparatus for automatically controlling the standing wave ratio in the output wave guide of an externally tunable oscillatory device having means for tuning the device and a motor for driving the tuning means, said apparatus comprising, a standing wave introducer having a cavity and a movable plunger therefor for varying the standing wave ratio in the wave guide, a motor for positioning the plunger in the cavity, a source, for energizing the motors, switching means for de-energizing the introducer motor whenever the plunger is moved a prescribed amount, a switch for controlling the energizing of the introducer motor, a' worm driven by the tuning motor for reciprocating the switch over a fixed path, a plurality of cams adjustably positioned along the path for actuating the switch and means operable when the switch is moved to the end of the path for reversing the direction of rotation of the worm and for preparing the introducer motor for reversing the direction of moving the plunger.

' 5. Apparatus for automatically controlling the stand ing 'wave ratioin the output wave guide of an externally tunable oscillatory device having a driver for tuning the device for oscillation over a frequency range, comprising an adjustable'standing' wave introducer for the wave guide, a motor for adjusting the introducer, means for de-energizing the introducer'motor when the introducer is adjusted a prescribed amount and means controlled by the driver for selectivelyenergizing the introducer motor when the device is tuned for oscillation at predetermined frequencies.

' 6. Apparatus for automatically controlling the standing wave ratio in the output wave guide of an externally tunable oscillatory device having a driver for tuning the device for oscillation over a frequency range, comprising a standing wave introducer having a cavity and a movable plunger therefor for varying the standing wave ratio in the, wave guide, screw advancing means for the plunger, a motor for driving the screw advancing means, a source for energizing the motor, switching means controlled by the screw advancing means for deenergizing the plunger motor whenever the plunger is moved a prescribed amount and means controlled by the driver for selectively energizing the introducer motor when the device is tuned for oscillation at predetermined frequencies. i

7. Apparatus for automatically controlling the standing wave ratio in the output wave guide of an externally tunable magnetron having a motor for tuning the magnetron for oscillation over a fixed frequency range, said apparatus comprising a standing wave introducer having a cavity and a movable plunger therefor for varying the standing wave ratio in'the 'wave guide, screw advancing means for the plunger, a motor for driving the plunger screw advancing means, a source for energizing the motors, switching means controlled by the screw advancing means for de-energizing the plungerv motor whenever the plunger is moved a prescribed amount, a switch for controlling the energizing of the introducer motor, a worm driven by the tuning motor for reciprocating the switch over a given path and a plurality of cams adjustably positioned along the path for actuating the switch;

8. Apparatus for automatically controlling the standing wave ratio in the output wave guide of an externally tunable magnetron having a motor for tuning the magnetron for oscillation over a fixed frequency range, said apparatus comprising a standing wave introducer having a cavity and a movable plunger therefor for varying the standing wave ratio in the wave guide, screw advancing means for the plunger, a motor for driving the plunger screw advancing means, a source for energizing the motors, switching means controlled by the screw advancing means for de-energizing the plunger motor whenever the plunger is moved a prescribed amount, a switch for controlling the energizing of the introducer motor, a worm driven by the tuning motor for reciprocating the switch over a given path, a plurality of cams adjustably positioned along the path for actuatin the switch and means operable when the switch is moved to the end of the path for reversing the direction of rotation of the Worm and for preparing the introducer motor for reversing the direction of moving the plunger.

References Cited in the file of this patent UNITED STATES PATENTS 

